To avoid pulling up floors etc to run a new shower cable, I am routing a 10mm twin & earth from the consumer unit, through the outside wall of the house, along the outside wall at 7ft height to re-enter the house at first floor level, then up to a 10kw shower in the bathroom. The external run is inside our roofed over and enclosed side passage. Total cable run length is 10M. Do I need to run this cable in a conduit or is it ok exposed and clipped correctly to the outside wall at 7feet high? Help would be appreciated.